.bg {
    background: url("https://community-wscdn.xiaomawang.com/picture/e62c68659d21ea42441d196e85e978f865fbae8e.jpg") no-repeat center center;
    background-size: cover;
    height: 1000px;
    margin-top: 80px;
    position: relative;
}

.bg .record-table {
    width: 80%;
    margin: 0 auto;
    background: #fff;
    position: absolute;
    top: 40px;
    left: 50%;
    transform: translateX(-50%);
    height: 800px;
    overflow: auto;
}